It is known to provide flexible webs of material having a plurality of tubular channels through which air can flow, so that heated or cooled air can pass along the air channels to provide a warmed or cooled pad of material. Such materials can be used in temperature controlled garments, temperature controlled seats for automotive use, and temperature controlled blankets or mattresses.
Typically, such temperature controllable materials may be formed from a thermo setting plastics material, having a plurality of relatively thicker fibers arranged in a first direction, crossed by a plurality of laterally undulating thinner fibers in a second direction both above and below the thicker fibres. Parallel to the thicker fibers in the first direction, may be provided a plurality of thermo setting fibers, such that when the thicker fibers in the first direction are bonded to the thinner fibers in a second direction and heat is applied, the thermo setting thinner fibers in the first direction contract, thereby pulling the thicker fibers into a series of vertical undulations, and forming a plurality of air channel between a sandwich of upper and lower relatively thinner fibers.
This hollow material can be covered with upper and lower layers of fabric to produce a hollow resilient pad which is comfortable to sit or lay on, and through which air can be passed. By temperature controlling the air, the pad can be heated up or cooled down.
However, the usability and acceptance by consumers of air temperature controllable materials has been held back by the size, weight, noise and inconvenience of air heating and cooling devices for use with temperature controllable fabrics. For example a known heating device for an air temperature controlled mattress has dimensions of the order 40 cm width, 80 cm length, and 50 cm height, which is an inconveniently sized air supply unit for a domestic use.